Antennas that emit electronically steered beams are known in the art as “phased array antennas.” Such antennas are used worldwide in a wide variety of commercial and radar applications. They typically are produced from many small radiating elements that are individually phase controlled to form a beam in the far field of the antenna.
Among other things, phased array antennas are popular due to their ability to rapidly steer beams without requiring moving parts. One problem, however, is their cost—they can cost on the order of $1000 per element. Thus, for a 1000 element array, the cost can reach or exceed $1,000,000.